An organic EL device is a light emitting device of a spontaneous emission type and is expected as a light emitting device for display or lighting, and active researches thereof have been made in recent years. Reduction in driving voltage of the organic EL device and elongation in operation life thereof are indispensable factors for accelerating actual utilization of the device, and they are large problems particularly for blue light emitting devices. Accordingly, organic luminescent materials have been investigated in various manners, and an improvement in styrylallene, anthracene derivatives, coumarin derivatives and the like has been promoted aiming at an improvement in luminous efficiency of the light emitting device and elongation in operation life thereof (for example, Materials Science and Engineering:R: Reports Volume 39, Issues 5 to 6, Pages 143 to 222, 2002 (non-patent document 1), JP H17-139390 A/2005 (patent document 1) and JP H16-6222 A/2004 (patent document 2)). In the above devices, however, Alq3 (tris(8-hydroxyquinoline)aluminum) is used as an electron transport material in many cases, and a large part thereof has high driving voltage and low luminous efficiency.
Then, development of high performance electron transport materials including silole derivatives and phenanthroline derivatives has been promoted, and red light emitting devices and green light emitting devices have been reported, but devices having a markedly long life have not ever been reported in blue light emitting devices (for example, JP H17-32488 A/2005 (patent document 3), JP H17-108720 A/2005 (patent document 4), Proceedings of the 10th International Workshop on Inorganic and Organic Electroluminescence (non-patent document 2) and Chem. Mater. 13, 2680 to 2683, (2001) (non-patent document 3)).    Patent document 1: JP H17-139390 A/2005    Patent document 2: JP H16-6222 A/2004    Patent document 3: JP H17-32488 A/2005    Patent document 4: JP H17-108720 A/2005    Non-patent document 1: Materials Science and Engineering:R: Reports Volume 39, Issues 5 to 6, Pages 143 to 222, 2002    Non-patent document 2: Proceedings of the 10th International Workshop on Inorganic and Organic Electroluminescence    Non-patent document 3: Chem. Mater. 13, 2680 to 2683, (2001).
Under the situation described above, desired are a coumarin compound which is optimally applied to an organic electroluminescent device improved in luminous efficiency, device life, driving voltage and the like in a blue light emitting device and an organic electroluminescent device and a display unit using the same.